In-phase and the quadrature (I/Q) signal processing is vastly utilized in conventional communication transceivers. However, the I/Q signal processing has amplitude and phase mismatching between the in-phase and the quadrature branch, which is also called I/Q imbalance or I/Q mismatch. The I/Q imbalance is one of the severe performance bottleneck in transceivers. The amplitude (gain) and phase mismatches between in-phase signal and quadrature signal degrade the signal-to-noise ratio (SNR) in a receiver (RX) side and the error vector magnitude (EVM) in a transmitter (TX) side. The I/Q imbalance mainly stems from the local oscillator (LO). Therefore, it is necessary to reduce I/Q imbalance in a LO generator.